To observe the effect of certain active components from traditional Chinese medicinal herbs on Aβ secre- tion rates with L-[35S]-Methionine

β-amyloid peptide (Aβ) in SK-N-SH cell lines stably transfected with APP695 was metabolically labeled with L-[35S]-Methionine. The supernatant from culture medium was immunoprecipitated with monoclonal antibody against Aβ22-35

Western blot was carried out

and the gray density of Aβ band in the autoradiograph was measured by an image analysis system. The active components from certain traditional Chinese medicinal herbs (ZMS from Zhimu and AST and HT from Huangqi) were added to the culture medium at a final con- centration of 10-5 mol/L. An Aβ band in the autoradiograph was clearly viewed in the culture medium after 24 h in- corporation of [35S]-Methionine which represent the secretion rate of Aβ by the cells. One of the 3 tested components (AST) could significantly reduce the Aβ secretion rate while the other two showed no effect. The preliminary result showed that certain active component from traditional Chinese medicines could decrease the Aβ secretion rate but other active components could not. Combined use of the AST and ZMS was more effective than single AST.